1. Field of Invention
The present invention relates to an electronic seal and, more particularly, to an electronic seal equipped with a breakage-detecting circuit for detecting, recording and reporting any event of breakage of the electronic seal.
2. Related Prior Art
An electronic seal based on radio frequency identification (“RFID”) and a combinative communication framework for example can be used to seal a container trailer truck or a bond truck so that the security of goods contained in the vehicle and information of the content of the goods can be transmitted and identified. Electronic seals are classified into active electronic seals and passive electronic seals, based on whether they are equipped with batteries. Passive electronic seals can be found in Taiwanese Patents M358380, M328051, M260603 and I289795 for example. These passive electronic seals are disposable, i.e., they cannot be reused. Therefore, these passive electronic seals are not friendly to the environment. Furthermore, these passive electronic seals cannot actively record events of breakage and the points of time of the events of breakage or immediately report the events of breakage via communication device.
An active electronic seal, which includes a battery, generally performs more functions than a passive electronic seal. An active electronic seal can be found in Chinese Patent Application Publication ZL200620047910.6. As disclosed in Chinese Patent Application Publication ZL200620047910.6, the active electronic seal includes a global positioning system (“GPS”) module, a microprocessor, a receiver and a transmitter. However, as disclosed in Chinese Patent Application Publication ZL200620047910.6, the active electronic seal includes a disposable plug and socket that cannot be reused so that the cost of the application of the active electronic seal is also high.
Another active electronic seal can be found in U.S. Pat. No. 6,069,563. As disclosed in U.S. Pat. No. 6,069,563, the active electronic seal is equipped with an active-detective circuit for detecting events of breakage. However, as disclosed in U.S. Pat. No. 6,069,563, the active electronic seal is also a one-time disposable device that cannot be reused so that the cost of the application of the active electronic seal is also high.
Furthermore, all mechanical seals are one-time disposable, i.e., they cannot be reused. The mechanical seal can be observed from its outside to determine whether it has been broken.
An electronic seal can be equipped with a breakage detecting and recording apparatus for detecting external parameters such as light, heat and temperature. Such external parameters of a container or a carriage of a bond truck are detected and recorded before and after door sealing, then compare those data to determine whether the door has been opened illegally. An electronic seal can be used together with a GPS and GSM, GPRS, WCDMA or HSDPA communication to position the electronic seal and exchange security and transportation information of goods contained in the container or the carriage.
When an active electronic seal fails, it is often because the battery has run out of electricity or sometimes because the active electronic seal is broken. Hence, it is generally difficult to determine whether an active electronic seal fails because it has run out of electricity or it has been broken or it has been disabled without breakage. However, it is important to determine whether an active electronic seal fails because it has run out of electricity or it has been broken or it has been disabled to determine the security of the container or the carriage in practical usage.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.